Right now it is the season for making jam! This may come as a surprise for those of you who think this is a mainly countryside activity, but in fact the city of Birmingham has an abundance of open spaces with plum and cherry trees, and the Bull Ring market is laden with fresh berries from the Vale of Evesham. Today I was going for a walk up in Holly Road near St. Augustine's, Edgbaston (an Anglo - Catholic church I know well and where I sometimes practice on its fine organ), and all across the pavements were windfall plums and damsons. So I gathered some of them up, brought them home and boiled up two jars of very fine plum jam.
The method is relatively simple, and is pretty much the same for most soft fruits. You take the fruit, often in semi - decayed and battered condition, wash them, and if necessary, then cut out the stones. Then weigh them, and for the same weight of fruit you measure out the same measure of sugar. (Hence 2 pounds of sugar for 2 pounds of fruit. This may seem excessive, but this is the amount needed for the jam preserve and set.)
Then render down the fruit in a saucepan at low heat with a small sliver of liquid at the bottom, and when the fruit has broken down, add the sugar in stages, making sure it has completely dissolved to the last crystal. Then add a tiny pat of butter (to prevent excessive foaming), and bring the mixture to boil rapidly for 5 to 10 minutes, until the jam sets. You test if it has set by putting a small dribble on a cold plate, and tip it to see if it has.
The jars have also to be sterilised and preheated, otherwise they will crack with hot jam. To do this, take wet jars with a touch of water inside with metal lids loosely fitted (otherwise they might burst!), and place them upside down in an oven at around 125 degrees Celsius. A word of warning: boiling jam causes very serious and nasty burns, so be careful in handling it!
In a week or so the blackberries in my back garden and around the area will be ready for harvesting, and so I can make up a whole job lot of bramble Jam. This tends to produce a hard, rather crunchy jam (which I'm very fond of), and hence some people make a jelly out of them. The fruit is stained through muslin cloth after boiling, and then the sugar added to the juice afterwards and boiled up to set.